In this continuing study of palate morphogenesis and effects of teratogens in causing cleft palate, the proposed research will be to determine whether the contractile proteins of the palate play a role in shelf movement. Morphologic studies will be continued employing electron microscopy and histochemical ATP-ase to localize the contractile proteins. The effects of neuromuscular blocking agents such as d-tubocurarine will be further employed to determine the role of palatal contractile proteins. Studies on the effect of triamcinolone will be undertaken. After administration of triamcinolone to the pregnant dam, its effect on the synthesis of actin and myosin by the incorporation of H3-leucine into cultured explants of palate and tongue will be measured. Next, studies on the effect of triamcinolone on the degradation of actin and myosin in these tissues will be carried out.